The mixing of liquid solutions finds numerous applications such as liquid-liquid mixing and liquid-solid (e.g., powder) mixing. For example, in preparing baby formula, a predetermined amount of either a liquid concentrate or a powder is mixed with a predetermined amount of water. Often the water and concentrate or powder are poured into a bottle. The bottle is then rigorously shaken to mix the water and concentrate or powder to make the baby formula. The mixing process induces large amounts of air in the formula that, if digested by the baby, can cause colic or other discomforts to the baby. Since the formula is mixed directly into the bottle used for feeding, a new bottle needs to be prepared for each feeding. Thus, the steps of measuring out predetermined amounts of water and concentrate or powder are repeated numerous times a day.
Larger quantities of formula (e.g., more than one feeding worth) can be pre-made and stored in an air tight container. However, some formulas can partially separate while being stored. As a result, the formula has to be remixed before it can be used. Often, the mixing is done using a spoon which has to be obtained separately from the pitcher.
There is need, therefore, for a pitcher having a mixing device therein that is capable of liquid-liquid mixing and liquid-solid mixing without inducing large amounts of air into the mixture.